FREE entry and a great day out. Lots of exhibitions and areas to explore. They also run lots of special events throughout the year and a monthly Experitots event for under 5's which is great.
Manchester Museum
FREE Lots of great exhibitions including "Stan" the T Rex, and Reptile area. They run hands on sessions for children also.
Eureka, Halifax
Hat Works, Stockport
FREE Dedicated to the Hatting Industry, see Hats throughout the ages. Large family fun area, where you can try hats on, and have a go at making your own. Surpisingly a lot of fun.
Imperial War Museum